Application Note EDXRF3267
Scope
This application note demonstrates the measurement of copper (Cu) in treated wood and wood treatment solutions using the Rigaku NEX QC II energy dispersive X-ray fluorescence (EDXRF) analyzer.
Background
Wood treatments help protect lumber from fungi, insects, UV damage, and general weathering. Copper- and copper oxide-based wood preservatives are widely used in residential and commercial construction projects, including building foundations, fencing, decking, and playground structures. During the treatment process, copper concentration in the treatment solution must be carefully monitored to maintain consistent product quality while minimizing preservative consumption, reducing operating costs, and preventing product rejection. Copper (Cu) or copper oxide (CuO) levels are then measured in both the treatment solution and the finished wood to ensure proper preservative retention. EDXRF provides a fast, simple, and reliable method for copper analysis throughout the quality control process.
Calibration – Cu in wood
An empirical calibration was built using a set of assayed wood standards.
| Element: Cu Units: % |
||
| Sample I.D. | Standard value | Calculated value |
| A | 0.059 | 0.063 |
| B | 0.139 | 0.133 |
| C | 0.196 | 0.193 |
| D | 0.277 | 0.279 |
| E | 0.362 | 0.366 |
| F | 0.516 | 0.513 |
Correlation plot Cu in wood
Repeatability – Cu in wood
To demonstrate repeatability (precision), the low and high samples were chosen from the set of calibration standards. Each sample was measured in static position.
| Element: Cu Units: % |
||||
| Sample I.D. | Standard value | Average value | Std. dev | % Relative |
| A | 0.059 | 0.0629 | 0.0001 | 0.2 |
| F | 0.516 | 0.5112 | 0.0005 | 0.1 |
Calibration – Cu in solution
An empirical calibration was built using a set of assayed wood standards.
| Element: Cu Units: % |
||
| Sample I.D. | Assay Value | Calculated Value |
| 1 | 0.390 | 0.400 |
| 2 | 0.700 | 0.700 |
| 3 | 1.020 | 0.993 |
| 4 | 1.240 | 1.231 |
| 5 | 1.410 | 1.439 |
| 6 | 1.630 | 1.643 |
| 7 | 2.260 | 2.249 |
Correlation plot Cu in solution
Repeatability – Cu in solution
To demonstrate repeatability (precision), the low and high samples were chosen from the set of calibration standards. Each sample was measured in static position.
| Element: Cu Units: % |
||||
| Sample I.D. | Standard value | Average value | Std. dev | % Relative |
| 1 | 0.390 | 0.3992 | 0.0004 | 0.1 |
| 7 | 2.260 | 2.2561 | 0.0030 | 0.1 |
Conclusion
The results detailed here show the Rigaku NEX QC II’s ability to provide fast, simple, and reliable measurement of copper (Cu) in treated wood and wood treatment solutions. The Rigaku NEX QC II supports quality control throughout the treated lumber production process, giving an affordable means of optimizing product quality while reducing costs and helping to minimize product rejection and waste.
